4.3 Analysis of the community composition of Insect pollinators
The measured environmental variables (Elevation, humidity, air
temperature, and flower resource abundance) are found to have a
significant association with the pollinator’s community. Species
abundance of pollinators was concentrated in the managed habitat and
open trails which were open to the high amount of solar exposer.
Activities of the insect pollinators are also highly influenced by such
sun exposures (McKinney & Goodell, 2010; Sydenham et al., 2016).
Similarly, flower resource abundance was the next positive influencing
factor for insect pollinators. The mixture of wildflowers could be a
good attraction for all these pollinators as this kind of relation of a
different group was also reported in the previous study (Carreck &
Williams, 2002).
The complex environmental gradient of high altitude affects the
abundance of different taxa of pollinators (Warren et al., 1988). As
expected, with the elevation, the abundance of pollinators declined. The
reason could be either decreasing of bee and fly attracted flowers or
their limited number in higher altitude (Arnold et al., 2009). The plant
communities at the high altitude limit the vascular plant and
availability of insect pollinators (Mani, 1962). The atmospheric
temperature and flower resource abundance have a negative correlation
with elevation. Temperature is an important factor for defining the
plant composition at higher altitudes (Subedi et al., 2020) and hence
alters pollinator abundance. Only a few species of hoverflies that don’t
have specific food choices (Kearns, 1992) and big size bees, for
instance, Bombus species that can thermoregulate and forage at
low temperature were found in the highest altitude of our study area.
RDA
Among Hymenoptera, Apis cerana and A. mellifera were
mainly determined by the flower abundance of the Buffer zone whileBombus eximius and B. flavescens were associated with
humid forest. The explanation for the Apis spp. could be their
preference on floral resources near the nesting area like small size
bees (Vulliamy et al., 2006; Gathmann & Tscharntke, 2002) so that they
could gather maximum nectar to support the large bee colony (Potts et
al., 2003). Large body–sized bees like Bombus spp. could travel
away from the nesting area for foraging (Greenleaf et al., 2007) and
humid areas to avoid hotter day temperatures (Willmer, 1983).Aglais caschmirensis is the most abundant and frequently seen
butterfly in all kinds of habitats (Irungbam et al., 2017). This could
be the reason for its presence in the forest as well as managed habitat
in our study area. Similarly, the association of Episyrphus
balteatus in the human habitat indicates the preference for vegetables
such as coriander, buckwheat (Pinheiro et al., 2015) as their host
plant. The maximum areas of human habitat were cultivated land.